A conventional torque spring is made of steel wire which is wound in a spiral form. A shaft is installed inside the spring and anchors are installed on both ends thereof. One side anchor is rotatable on an axis which is the center of the spiral steel wire. As the spiral steel wire is twisted, the steel wire reacts against the applied external force to return the spring to its previous shape before twisting.
Here, the effective diameter of the spiral steel becomes smaller by the torsion action, and the surface of the inside shaft and the steel wire come closer to each other. Depending on the effective diameter of the spiral steel and the inside shaft diameter, these two pieces make contact. When contact is made, the contact section without any movement generates friction motion. If the shaft diameter is very small so that there is no contact, snaking motion is generated by the spiral steel wire more easily, and thus spring action cannot be obtained on the total winding of the spiral steel wire. Contact by the snaking is also generated by a degree of snaking motion. Effects of the contact and snaking cause some problems of planned durability maintenance.
The torque shock absorber device of the present invention solves the problems described above, reduces contact wear and snaking, and maintains the durability of the spring.